[SPARK-17186][SQL] remove catalog table type INDEX

## What changes were proposed in this pull request?

Actually Spark SQL doesn't support index, the catalog table type `INDEX` is from Hive. However, most operations in Spark SQL can't handle index table, e.g. create table, alter table, etc.

Logically index table should be invisible to end users, and Hive also generates special table name for index table to avoid users accessing it directly. Hive has special SQL syntax to create/show/drop index tables.

At Spark SQL side, although we can describe index table directly, but the result is unreadable, we should use the dedicated SQL syntax to do it(e.g. `SHOW INDEX ON tbl`). Spark SQL can also read index table directly, but the result is always empty.(Can hive read index table directly?)

This PR remove the table type `INDEX`, to make it clear that Spark SQL doesn't support index currently.

## How was this patch tested?

existing tests.

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14752 from cloud-fan/minor2.

5 files changed, 6 insertions, 10 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
index f7762e0f8a..83e01f95c0 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
@@ -200,7 +200,6 @@ case class CatalogTableType private(name: String)
 object CatalogTableType {
   val EXTERNAL = new CatalogTableType("EXTERNAL")
   val MANAGED = new CatalogTableType("MANAGED")
-  val INDEX = new CatalogTableType("INDEX")
   val VIEW = new CatalogTableType("VIEW")
 }
 
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala
index 21544a37d9..b4a15b8b28 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/tables.scala
@@ -620,12 +620,11 @@ case class ShowPartitionsCommand(
      * Validate and throws an [[AnalysisException]] exception under the following conditions:
      * 1. If the table is not partitioned.
      * 2. If it is a datasource table.
-     * 3. If it is a view or index table.
+     * 3. If it is a view.
      */
-    if (tab.tableType == VIEW ||
-      tab.tableType == INDEX) {
+    if (tab.tableType == VIEW) {
       throw new AnalysisException(
-        s"SHOW PARTITIONS is not allowed on a view or index table: ${tab.qualifiedName}")
+        s"SHOW PARTITIONS is not allowed on a view: ${tab.qualifiedName}")
     }
 
     if (tab.partitionColumnNames.isEmpty) {
@@ -708,7 +707,6 @@ case class ShowCreateTableCommand(table: TableIdentifier) extends RunnableComman
       case EXTERNAL => " EXTERNAL TABLE"
       case VIEW => " VIEW"
       case MANAGED => " TABLE"
-      case INDEX => reportUnsupportedError(Seq("index table"))
     }
 
     builder ++= s"CREATE$tableTypeString ${table.quotedString}"
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/MetastoreRelation.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/MetastoreRelation.scala
index 195fce8354..d62bc983d0 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/MetastoreRelation.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/MetastoreRelation.scala
@@ -80,7 +80,6 @@ private[hive] case class MetastoreRelation(
     tTable.setTableType(catalogTable.tableType match {
       case CatalogTableType.EXTERNAL => HiveTableType.EXTERNAL_TABLE.toString
       case CatalogTableType.MANAGED => HiveTableType.MANAGED_TABLE.toString
-      case CatalogTableType.INDEX => HiveTableType.INDEX_TABLE.toString
       case CatalogTableType.VIEW => HiveTableType.VIRTUAL_VIEW.toString
     })
 
diff --git a/sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala b/sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala
index 9b7afd4628..81d5a124e9 100644
--- a/sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala
+++ b/sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala
@@ -379,8 +379,9 @@ private[hive] class HiveClientImpl(
         tableType = h.getTableType match {
           case HiveTableType.EXTERNAL_TABLE => CatalogTableType.EXTERNAL
           case HiveTableType.MANAGED_TABLE => CatalogTableType.MANAGED
-          case HiveTableType.INDEX_TABLE => CatalogTableType.INDEX
           case HiveTableType.VIRTUAL_VIEW => CatalogTableType.VIEW
+          case HiveTableType.INDEX_TABLE =>
+            throw new AnalysisException("Hive index table is not supported.")
         },
         schema = schema,
         partitionColumnNames = partCols.map(_.name),
@@ -757,7 +758,6 @@ private[hive] class HiveClientImpl(
         HiveTableType.EXTERNAL_TABLE
       case CatalogTableType.MANAGED =>
         HiveTableType.MANAGED_TABLE
-      case CatalogTableType.INDEX => HiveTableType.INDEX_TABLE
       case CatalogTableType.VIEW => HiveTableType.VIRTUAL_VIEW
     })
     // Note: In Hive the schema and partition columns must be disjoint sets
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveCommandSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveCommandSuite.scala
index 76aa84b194..df33731df2 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveCommandSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveCommandSuite.scala
@@ -424,7 +424,7 @@ class HiveCommandSuite extends QueryTest with SQLTestUtils with TestHiveSingleto
       val message4 = intercept[AnalysisException] {
         sql("SHOW PARTITIONS parquet_view1")
       }.getMessage
-      assert(message4.contains("is not allowed on a view or index table"))
+      assert(message4.contains("is not allowed on a view"))
     }
   }